It seems that "Display Assemblers" controls the display of the needed Miners for the resource outputs, as opposed to what I would assume is expected behavior of it displaying with "Display Miners/Pumpjacks".
Agreed this is a bug. "Display Miners/Pumpjacks" should be the only thing that toggles if Miners appear on "infinite" nodes for things such as ore or water.
It seems that "Display Assemblers" controls the display of the needed Miners for the resource outputs, as opposed to what I would assume is expected behavior of it displaying with "Display Miners/Pumpjacks".